A Dallas man who was in contact with the first person to be diagnosed with the Ebola virus in the U.S. said in an interview that the Liberian native had been weak and ill in an apartment after trying to seek help at a hospital days earlier.

Joe Joe Jallah said he met the man diagnosed with Ebola, Thomas Eric Duncan, last week when visiting Mr. Jallah’s former wife, Louise Troh, the same woman Mr. Duncan had come to see in the U.S.

Numerous members of the Liberian community in North Texas confirmed that Mr. Duncan traveled to the U.S. to visit Ms. Troh, who is also from Liberia. Ms. Troh declined to speak about the situation when reached by phone.

Mr. Jallah, who believed that this was Mr. Duncan’s first trip to the U.S., said he was anxious to hear from Mr. Duncan about the situation in Liberia, where Ebola has ravaged parts of the country.

He listened as Mr. Duncan described how dire things had become in Liberia, and how rigorous the health screenings were during his trip to the U.S.

Several days later, on Saturday, Mr. Jallah said he had heard that Mr. Duncan had fallen ill.

Concerned, Mr. Jallah went back to the apartment to check on Mr. Duncan.

“He was lying down on the floor with a comforter. He said he was sick and that he had no appetite,” Mr. Jallah said.

‘I said, ‘Did you go to the hospital? He said, ‘Yes, but they did nothing for me,’” Mr. Jallah recalled. “I said, ‘You should eat so you can gain strength.’ ”

An employee with The Ivy Apartments complex goes door-to-door placing flyers. A man staying at the complex with family was diagnosed with having the Ebola virus. Associated Press

Mr. Jallah left to go to work, but returned the next day after his daughter, who lives with Ms. Troh, called, sounding frantic, saying that Mr. Duncan was still ill.

“When I went back, the man was sitting on the bed. He was drinking coffee or tea. My daughter said let’s call 911, he still doesn’t have an appetite,” Mr. Jallah recounted.

Mr. Jallah agreed. Ms. Troh and her family were growing worried, he said. They all knew that Ebola was tearing through their homeland, though at no time had Mr. Duncan talked about coming into contact with sick people before traveling, Mr. Jallah said.

They considered carrying Mr. Duncan, who appeared increasingly weak, outside to a car and driving him to the hospital, but decided to wait for an ambulance instead.

When the ambulance arrived, Mr. Jallah said he told emergency workers that Mr. Duncan was sick and from Liberia. The workers subsequently put masks over their mouths.

“My daughter was scared,” said Mr. Jallah. “She didn’t know what was happening.”

Mr. Jallah, who is being monitored by health officials because of his contact with Mr. Duncan, said he is worried about the well-being of his family members as well as for Mr. Duncan.

He is also struggling to understand how Mr. Duncan was able to arrive in the U.S. despite being sick.